Managing ginger rhizome rot (Part 1)

Ginger rhizome rot is considered one of the major limiting actors of ginger production in Jamaica.

The main pathogens associated with this disease are fungi, such as Fusarium spp, Rhizoctonia solani, and Pythium sp, bacterial pathogens and parasitic nematodes.

Rhizome rot has been found in all major ginger-production areas in Jamaica. The disease is also spread by infected seed pieces from the previous crop, although these may appear symptomless.

Prolonged periods of wetness and poor drainage are highly favourable for rapid development of rhizome rot. Repeated cultivation of ginger on the same plots of land greatly contributes to the build-up of diseases and nematodes.

Symptoms of ginger rhizome rot are often described by local farmers as 'boils'. Diseased rhizomes show several characteristics:

A brown discoloration A shrivelled appearance

The affected ginger eventually decays, leaving the outer shell intact with only fibrous internal tissue remaining.

In case of fusarium infection, young plants develop leaf spot and leaf yellowing which result in plant wilt ('quailing') over a period of several weeks. In the case of bacterial infection, plant wilt is more progressive and sees a rapid yellowing of leaves and stem, plant collapse, soft rot of young rhizomes, as well as the presence of an unpleasant rotting odour.

Sloping terrain provides ideal conditions for spread of diseases during the rains, when water moves along the slope and carries diseased spores ('seeds').

Contributed by the Communications and Public Relations Department of the Rural Agricultural Development Authority (RADA) . For further information contact RADA via 1-888-ASK-RADA OR 1-888-275-7232, or visit www.rada.gov.jm